In traditional cable networks, a broadcast stream containing program material, e.g., a TV show, typically contains one or more splice points (commonly referred to as advertisement breaks) allowing for the insertion of advertisements. Many cable operators utilize these splice points to insert local advertisements or for self-promotion. For example, a cable operator may broadcast an advertisement for a local car dealership at a splice point during the TV show “Friends.” Although this form of advertising has been used for years, it is inefficient because in many instances the majority of subscribers watching the respective program material may not be a member of the audience for whom the advertisement is intended. For instance, in the example given above, many teenagers watch “Friends,” but relatively few teenagers are potential purchasers of automobiles.
In response to this problem, an improved technique known as targeted advertising has been used recently in some cable networks. Targeted advertising generally allows a cable operator to generate one or more sets of “targeted advertisements” aimed at various demographic groups, and deliver the targeted advertisements to those groups. Several techniques exist for delivering targeted advertisements to subscribers' set-top terminals (STTs) in a cable television network. According to one such technique, a cable operator's headend facility provides one or more sets of advertisements targeted at various demographic groups. Each STT in the network receives these targeted advertisements at opportune times, such as between 2:00 am and 6:00 am when the STT is not active, and stores them in memory. Subsequently, when subscribers are watching a cable program, the STT detects an upcoming advertisement break in the program and substitutes one or more of the targeted advertisements stored in memory for the regularly scheduled advertisements. The STT may use demographic information associated with the program currently being watched, or subscriber-related data collected by the STT, to select an appropriate substitute advertisement from among those stored in memory. In accordance with this technique, the targeted advertisements are inserted into the broadcast stream being received by the STT.
In accordance with another technique, a cable operator assigns, for a given program channel, a predetermined number of transmission channels to carry alternate targeted advertisements to the subscribers watching the given program channel. Using this technique, the cable operator prepares in advance a collection of targeted advertisements, without knowledge of the make-up of the actual audience of the given program channel at an advertisement break. To generate targeted advertisements, the cable operator utilizes a database containing demographic information describing the whole subscriber base. Typically, multiple targeted advertisement streams are generated for various demographic groups identified within the subscriber base. When an advertisement break occurs, the cable operator transmits the prepared streams of targeted advertisements through the respective transmission channels. Each stream of targeted advertisements contains control information indicating the demographic group for which the advertisements are intended. An STT in the network selects one of the streams of targeted advertisements based on one or more factors. These factors may include a demographic profile associated with the TV show currently being shown, or information known about the respective STT household. The STT tunes to the appropriate transmission channel, plays the selected stream of targeted advertisements during the advertisement break, and then re-tunes to the original TV show channel after the advertising break ends. However, this technique proves to be ineffective especially when members of a demographic group for which a targeted advertisement is intended are not present in the actual audience of the show.
The prior art techniques described above are inefficient for other reasons as well. For example, they require the installation and maintenance on STTs in the network of special software applications that perform tasks such as monitoring a program channel for advertisement breaks, maintaining and analyzing demographic information concerning the subscriber, and selecting one or more advertisements appropriate for the subscriber household. For many cable operators, it is costly and inefficient to install and maintain software applications in large numbers of STTs in a network.